Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['2917', '8755', 'U', '5663', 'k', '7767']

2917, 8755, 21, 5663, 11, 7767